Electronic structure and thermodynamic properties of platinum–lead oxides PbPt₂O₄ and Pb₂PtO₄ by ab initio methods

ABSTRACT

We report the electronic structure and thermodynamic properties of platinum–lead oxides PbPt₂O₄ and Pb₂PtO₄. The band structure is calculated by the full-potential, full-relativistic local orbital minimum basis (FPLO) method in the local density approximation, including the generalized gradient approximation (GGA) and GGA+U, respectively. The values of gaps in Pb₂PtO₄ were estimated as 0.47, 1.02, and 0.52 eV in GGA, GGA+U, and the full-relativistic GGA, respectively. Pb₂PtO₄ is a semiconductor, and PbPt₂O₄ is a metallic conductor with the small values of the density of states at the Fermi level. The effect of chemical disorder in Pb_2−xPt_1+xO₄ alloys is studied by the relaxation of the volume, shape, and the positions of atoms in the unit cell, using the Vienna Ab initio Simulation Package (VASP) method. The thermodynamic properties are computed in the quasi-harmonic Debye–Grüneisen model. The dependence of the thermodynamic parameters on the pressure and temperature is also presented.

KEYWORDS:

• Ab initio calculations
• thermodynamic properties
• phase diagram
• density functional theory
• electronic structural calculations

PACS:

• 31.15.-p
• 31.15.A-
• 31.15E-
• 71.15.Mb
• 71.20.Nr

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Science Centre (NCN) [grant number DEC-2011/01/B/ST3/02212].